American Megatrends Super Voyager LPX, User Manual

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Super Voyager LPX ISA Motherboard User's Guide
Advanced Setup,
Continued
External Clock for 100MHz DX4
This option specifies the external clock speed for a 100 MHz 486DX4
CPU. The settings are
50MHz or 33 MHz. The Optimal and Fail-Safe
default settings are 50MHz.
Important
The 486DX4 CPU must have the proper voltage.
Pins 1-2, 3-4, and 5-6 on J56 must be shorted.
A heat sink (U70) to change the CPU voltage from
5V to 3.3V must be installed. 3.3V CPUs cannot
be used unless this voltage regulator is installed.
A 100 MHz 486DX4 CPU can be configured in two ways:
This
option
CPU
Speed
External
Speed
Motherboard Jumper
Settings
50 MHz 100 MHz 50 MHz Pins 1-2 of J37 must be shorted.
J11, J12, and J15 should all be OPEN.
33 MHz 100 MHz 33.33
MHz
J37, J11, and J15 must be OPEN.
A shorting bridge must be installed on J12.
The setting of this option has no effect on the configuration of any other
type of Intel CPU. It only affects the 100 MHz 486DX4 CPU.